When to plant Onion in Zone 6b
In Zone 6b, Onion: start seeds indoors around Feb 4–Feb 18; transplant outdoors around Mar 18–Apr 1. Expect to harvest around Jun 26–Jul 10.
| Step | When |
|---|---|
| Start seeds indoors | Feb 4 – Feb 18 |
| Transplant outdoors | Mar 18 – Apr 1 |
| Harvest | Jun 26 – Jul 10 |
Tip: Day-length sensitive — match the variety (long/short day) to your latitude for big bulbs.
Zone 6b averages a last spring frost around Apr 15 and a first fall frost around Oct 25. These are zone averages — look up your ZIP for your exact area.
See the full Zone 6b calendar in the tool →